1. Field of the Invention
The present invention relates to an improved method for the manufacture of sliders. More particularly, the invention relates to an improved method for producing a positive camber on the air bearing surface (ABS) of a slider.
2. Description of the Background Art
Digital magnetic recording devices for data storage generally comprise a thin film magnetic recording disk and a head or transducer which is moved along or above the surface of the rotating disk to electromagnetically read and write information on the disk. Advanced thin film magnetic recording disks generally comprise a rigid substrate, a magnetic layer such as a cobalt-based metal alloy, a protective amorphous carbon layer and a lubricant layer, such as a perfluoropolyether disposed on the carbon overcoat.
During operation of the disk drive system, an actuator mechanism moves the magnetic transducer to a desired radial position on the surface of the rotating disk where the head electromagnetically reads or writes data. Usually, the head is integrally mounted in a carrier or support referred to as a xe2x80x9csliderxe2x80x9d. A slider generally serves to mechanically support the head and any electrical connections between the head and the rest of the disk drive system. The slider is aerodynamically shaped to glide over moving air and, therefore, to maintain a uniform distance from the surface of the rotating disk, thereby preventing the head from undesirably contacting the disk.
Typically, a slider is formed with an aerodynamic pattern of protrusions on the ABS which enable the slider to fly at a constant height close to the disk during operation of the disk drive.
The recording density of a magnetic disk drive is limited by the distance between a transducer and the magnetic media. One goal of air bearing slider design is to xe2x80x9cflyxe2x80x9d a slider as closely as possible to a magnetic medium while avoiding physical impact with the medium. Smaller spacings, of xe2x80x9cfly heightsxe2x80x9d, are desired so that the transducer can distinguish between the magnetic fields emanating from closely spaced regions on the disk.
It has been found that two important characteristics of the slider necessary to achieve and maintain the desired flying characteristics for the slider are crown and camber. Crown is the deviation from a planar surface in the direction of air flow with a concave shape defined as negative crown and a convex shape defined as positive crown. Camber is the deviation from a planar surface in a direction normal to the direction of air flow. A concave shape is defined as negative camber and a convex shape is defined as positive camber. Neither negative crown nor negative camber of the ABS is desired for sliders since this not only leads to variation in the flying height but also makes it more likely that the edges of the slider will damage the recording medium should there be inadvertent contact with the recording medium.
In manufacturing such read/write heads, a large number of sliders are fabricated from a single wafer having rows of the magnetic transducers deposited simultaneously on the wafer surface using semiconductor-type process methods. In one process embodiment, after deposition of the heads is complete, the wafer is cut into four quadrants. Each quadrant is then bonded to a lapping fixture and grounded on a lapping plate to provide accurate head dimensions. After lapping, single row bars of sliders are cut from the wafer quadrant. These row bars can optionally be lapped again, and the ABS design is etched in each slider using art-known lithographic techniques. Lastly, the row bars are adhered to suitable tape; and each bar is diced, i.e., separated with a diamond-cut saw into individual sliders, each having a magnetic head terminating at the ABS. Each slider is then cleanly removed from the tape, inspected to insure operability of the magnetic head, and attached to an actuator for use in a magnetic disk drive.
Unfortunately, the lapping process produces stresses in the row bars, causing them to bow or bend. This can result in undesirable negative ABS camber in the finished individual sliders. Therefore, there still is a need in the art for a slider manufacturing process which results in heads with positive camber.
It is, therefore, an object of the present invention to provide an improved method for the manufacturing of magnetic heads. Other objects and advantages will become apparent from the following disclosure.
The present invention relates to a method for producing sliders having positive camber on the ABS. The method comprises (i) scribing the ABS along a line between individual sliders, (ii) lapping the ABS of the slider row on a flat lapping plate, and (iii) producing a pattern of stress relief on the back side of the slider opposite the air bearing surface to create positive camber and crown in each individual slider in the slider row.